Golf club shaft and golf club using the same

Abstract

A golf club shaft extending from a tip end to a butt end and made of fiber reinforced resin, comprises a weight being in a range of from 30 to 55 g, a whole length LS between the tip end and the butt end, a center of gravity of the shaft located with a distance LG from the tip end, a ratio of the distance LG to the whole length LS being in a range of from 0.54 to 0.65, a tip end portion which has a length of 300 mm from the tip end toward the butt end, the tip end portion including fibers including a pitch based carbon fiber and a PAN based carbon fiber, and said fibers in the tip end portion comprising, in weight, the pitch based carbon fiber of from 15 to 25% and the PAN based carbon fiber of from 85 to 75%.

The invention claimed is: 
     
       1. A golf club shaft extending from a tip end to a butt end and made of fiber reinforced resin, comprising
 a weight being in a range of from 30 to 55 g, 
 a whole length LS between the tip end and the butt end, 
 a center of gravity of the shaft located with a distance LG from the tip end, 
 a ratio of the distance LG to the whole length LS being in a range of from 0.54 to 0.65, 
 a tip end portion which has a length of 300 mm from the tip end toward the butt end, 
 the tip end portion including fibers including a pitch based carbon fiber and a PAN based carbon fiber, and 
 said fibers in the tip end portion comprising, in weight, the pitch based carbon fiber of from 15 to 25% and the PAN based carbon fiber of from 85 to 75%. 
 
     
     
       2. The golf club shaft according to  claim 1 , wherein
 said PAN based carbon fiber in the tip end portion comprises a straight fiber being parallel with an axial direction of the shaft, and 
 the straight fiber is contained, in weight, in a range of from 50 to 80% of whole fibers in the tip end portion. 
 
     
     
       3. The golf club shaft according to  claim 1  or  2 , wherein
 said PAN based carbon fiber in the tip end portion comprises a bias fiber inclined at an angle of 45 degrees plus/minus 5 degrees with respect to an axial direction of the shaft, and 
 said bias fibers in the tip end portion are contained, in weight, in a range of from 5% to 25% of whole fibers in the tip end portion. 
 
     
     
       4. The golf club shaft according to  claim 1  or  2 , wherein
 the shaft has a flexural rigidity EI at a position of 100 mm length from the tip end of the shaft is not more than 2.0 kgf m 2 . 
 
     
     
       5. The golf club shaft according to  claim 1  or  2 , wherein
 the ratio of the distance LG to the whole length LS is in a range of from 0.55 to 0.64. 
 
     
     
       6. The golf club shaft according to  claim 1  or  2 , wherein
 the ratio of the distance LG to the whole length LS is in a range of from 0.56 to 0.63. 
 
     
     
       7. The golf club shaft according to  claim 1  or  2 , wherein
 said fibers in the tip end portion comprises, in weight, the pitch based carbon fiber of from 16 to 24% and the PAN based carbon fiber of from 84 to 76%. 
 
     
     
       8. The golf club shaft according to  claim 1  or  2 , wherein
 said fibers in the tip end portion comprises, in weight, the pitch based carbon fiber of from 17 to 23% and the PAN based carbon fiber of from 83 to 77%. 
 
     
     
       9. The golf club shaft according to  claim 1  or  2 , wherein
 the shaft has a flexural rigidity EI at a position of 100 mm length from the tip end of the shaft is in a range of from 0.9 to 1.8 kgf m 2 . 
 
     
     
       10. The golf club comprising a club shaft according to  claim 1  or  2 , and a golf club head.